This invention relates to multiparty conferences, and more particularly, to multiparty audio, video, or other types of conferences implemented over a data network using digital techniques.
Call conferencing is an old technology utilized to facilitate communications among a plurality of conference members. Such technology is conventionally utilized for audio communications over standard telephones. More recently, conferencing technology has also been utilized for video signals. A conventional conferencing system operates by patching together multiple parties via a conference bridge. A conference bridge operates by transmitting to each conference member a signal that represents the sum of all of the other conference members"" inputs. Thus, each member hears all the audio generated by the other members.
Conventional analog conferencing systems do not provide flexibility and ease of use for conference members. Specifically, there is no easy way for controlling which conference members receive any one or more particular signals. Rather, each conference member receives the sum of signals produced by all other conference members.
Another problem with conferences based upon conventional telephony is that the bandwidth utilized to transmit audio over a conventional telephony system includes a large amount of waste. This is because a circuit connection exists from each conference member to all other conference members. Much of the bandwidth of the circuit connection is idle a large amount of time.
The modern trend is to convey more and more audio and video traffic over data networks such as the Internet. This trend is applicable to conferencing systems as well. Use of the Internet maximizes the efficiency of the network because packets related to multiple different communications sessions can be conveyed over the same physical media. Thus, Internet based audio/video conferencing systems have emerged recently.
The use of digital techniques to implement conference calls allows a variety enhanced services to be implemented, and eliminates waste of bandwidth. Moreover, the conference bridge itself may be eliminated since conferencing is implemented by forwarding separate copies of a packet from an originating entity to multiple receiving entities. At the same time, digital conferencing techniques present their own problems. Digital conferences cannot be implemented by simply summing all of the inputs to create a signal for each particular conference member. Rather, the packets of data must be assembled, ordered properly and then conveyed appropriately. Additionally, the use of digital techniques provides that conferences may be divided into multiple conferences and reassembled, merged with other conferences, etc. All of this must be managed. In particular, messages of a conference must be managed to prevent collision.
A document dated Jun. 17, 1999, generated by the Internet Engineering Task Force describes basic techniques of arranging conferences over the Internet using digital techniques. The described technique solves some of the foregoing problems. The technique described therein is lacking in several aspects. In arranging for a conference, it uses a flooding technique wherein each member of the conference advises a member seeking to join the conference if members previously in the conference drop out. This flooding technique results in added overhead. Additionally, if a member attempting to join the conference is locked out by a present member of the conference, there is no easy technique for overriding such lockout. There are a variety of other cumbersome techniques used in the referenced system.
There exists no known technique for efficiently monitoring and managing conferences as they are set up, merged, split, and destroyed. There exists no known technique of efficiently adding members to an Internet based audio or video conference. In addition, there exists no known technique for efficiently preventing collisions between conference messages. Accordingly, there exists a need in the art for an improved technique of managing distributed multipoint conferences using the Internet and/or other similar data networks.
The above and other problems of the prior art are overcome in accordance with the present invention which relates to a technique of monitoring and controlling various aspects of conferences. In accordance with the present invention, a conference is set up by an xe2x80x9cinvitingxe2x80x9d member inviting others to join the conference. The invitation specifies which, if any, other members are presently in the conference and thus, the xe2x80x9cjoiningxe2x80x9d member knows with which other conference members to communicate. Importantly, if the invitation contains the identification of members that later drop out of the conference, those members are nonetheless contacted by the joining member as if they were in the conference. Those other members that have previously dropped out would then advise the joining member that they are no longer in the conference. The use of the original information in the invitation to specify conference members, rather than having the conference membership information updated each time the joining member contacts one of the specified conference members and that specified member indicates that some other member has dropped out of the conference, eliminates additional management and processing overhead when compared with prior systems.
In another embodiment, a joining member may be denied permission to join by any of the conference members. The particular member denying such admission may have its identity broadcast to the other members by the member attempting to join the conference. Other members may agree or disagree with the decision, and determine whether or not to override such decision to reject the joining member. Alternatively, the remaining conference members, if they want the joining member to join, may cut off the member rejecting the joining party from the conference.
In another embodiment, after a joining member is invited to join the conference by the inviting member, the joining member seeks and receives permission from each of the other conference members. As each conference member responds by granting or denying permission, the inviting party is kept apprised of the status.
In another embodiment, a conference member may invite other conference members to split the conference into two conferences. Invited members communicate with one another to establish the second conference.
In yet another embodiment, a technique for preventing collision of messages in a conference using a deference algorithm is used. The deference algorithm prioritizes messages to prevent collision.